In a typical magnetic storage system, digital data is stored in a series of concentric circles or spiral tracks along a storage medium. Data is written to the medium by positioning a read/write head assembly over the medium at a selected location as the storage medium is rotated, and subsequently passing a modulated electric current through the head assembly such that a corresponding magnetic flux pattern is induced in the storage medium. To retrieve the stored data, the head assembly is positioned again over the track as the storage medium is rotated. In this position, the previously stored magnetic flux pattern induces a current in the head assembly that can be converted to the previously recorded digital data. The location of data on the storage medium is identified by servo data. In an array reader magnetic recording system, the read/write head assembly includes an array of multiple read heads each positioned to read the target track. The separation of the read heads can vary, altering the phase offset between signals from the different read heads, particularly as the array of read heads is moved over the magnetic storage medium. The accuracy of estimations of the phase offset is important to correctly align and combine the signals.